double_balls = {'red': set(), 'blue': None, 'multiple': 1}

while True:
    print(double_balls['red'])
    if len(double_balls['red']) >= 3:
        break
    red = int(input('Red?: '))
    double_balls['red'].add(red)

blue = int(input('Blue?: '))
double_balls['blue'] = blue
print(double_balls)

